Wire spring



Sept 30, 1941- s. s. BERNSTIN I 2&257367 WIRE SPRING Filed June 24,l 1958 fr w Av ff! ff" f nal curve.

Patented Sept. 30, 1941 UNITED STATES PATENT OFFICE Appunti@ June 24, 193s, serial No. 215,627

(cl. s- 179) .3Claims.

This invention relates generally to wire springs, particularly that class of springs which have been termed hat' springs.

Fiat springs are ordinarily made of wire which has been bent to a sinuous shape. Such springs are used .generally in upholstery for backs or seats, ilat cushions, cushion seats and the like are usually secured in place with a slight longitudi- Ordinarily only the ends of the spring are secured and the spring is free to be bent beyond the plane of support. When bent beyond the plane of support, springs of the ordinary type with which I am familiar,'become less stiff and less able to resist the force against them. Some springs even fail to recover their original position if forced considerably beyond the plane 'of support. It is also true that the ordinary type of flat wire springs are not particularly stable against lateral displacement. Y

Therefore, it is an object of this invention. to provide a ilat wire spring of simple form and construction which is stiiIer than the ordinaryv flat spring of equal size. It is also an object of this invention to provide a flat spring which becornes increasingly stiff as it is bent beyond the plane of support and which-will very readily regain its original position when the force acting upon it is removed.

It is also an object of this invention to provide a iiat wire spring vof simple form and construction which is more resistant to lateral displacement than the ordinary type of spring and which is relatively stable in this respect.

It is a further object of this invention to provide a ilat wire spring which is formed of less material than other types of ilat wire springs of equal strength made. from like material having the same temper.

Ordinary ilat springs formed of wire having user. In this connection, where ordinary nat spring having a series of lateral U-shaperll undulations are used, it has been found necessary to use a relatively thin layer of padding material in the upholstery in order to prevent the padundulations of the spring and thereby preventing the springs from functioning. When only a relatively small amount of filling or padding is used the layer of material `adjacent the spring soon wears out due Ik) the fact that there is not enough padding to eifect a proper cushioning of the forces brought to bear on the upholstery.

' In view of the above disadvantages of the ordinary type iiat spring, it is a further object of this invention to provide a ilat wire spring which is designed to prevent undue wear of the cloth, padding, and other upholstery material with which .it` is associated, by providing a spring which has less pinching eiIect upon the material n with which it is associated than the ordinary typeof fiat wire spring. In this connection it is an object of this invention to provide a at spring having curved portions adapted to bear `against .the upholstery and support the major `the drawing thereof. Referring to the drawing which is for tions of the spring being ilat.

These and other objects will be apparent from and the following description illustrative purposes only,

Fig. 1 is a plan view of the spring of this invention vwhich has been shown in extended or flattened out position;

Fig. 2 is a side elevation of the spring when v unsecured;

Fig. 3 is a side elevation ofthe spring of Fig. 2 shown secured in position in a frame-work which is partly shown in section;

Fig. 4 is a fragmentary enlarged side elevation of one end 'of the spring of Fig. 3 vshown in conjunction with a fragmentary section of upholstery More particularly describing the invention, the ilat spring comprises a wire II which has. been undulated or bent into a sinuous shape to form alternately disposed diagonal portions I2 and U-shaped portions I3. The U-shaped portions I3 alternately face to opposite sides of the spring.

A particular feature of this invention is the provision of diagonal portions I2 which are 1ongitudinally curved as shown in Fig. 4. The U-shaped portions I3 are designed to be flat, that ding from working into the spaces between the is, each entire U-shaped portion lies in a single plane when the spring is unsecured as in Fig.. 2. 'Ihere is, of course, a slight distortion oi' the U-shaped portions when the spring is expanded to the position of Fig. 3. This constructionprovides a spring which when unsecured takes the position in which it is shown in Fig. 2, namely,

the springdescribes a general longitudinal curve forming a semi-circle.

It should be particularly noted, however, that although the entire spring may appear to describe a general longitudinal curve, in reality it Is only the diagonal portions I2 which are curved, and each of the U-shaped portions Il are flat.

The spring is designed to be secured in place in a frame,^such as I4, by spreading the ends of the spring to t into the securing eyes I 5. When thus secured in position in a frame, the spring is particularly eiective to yieldably resist the forces brought against it and if distorted or bent beyond the plane of support, as the spring is iincreasingly bent beyond the plane of support, it

becomes increasingly stiff and will readily spring back to its original position when the force acting upon it is removed. g Y i In Fig. 4 a. side elevation of a fragment o f the spring is shownas it would appear when associated with upholstery material. The material shown comprises a bottom piece I8 of burlapot asomo? 'series of lateral U-shaped undulations, it having been pointed out above that a thick layer of ller or padding cannot be used in connection with the -ordinaryvtype spring.

It should be apparentby referring to Fig. 1 that the spring of this invention requires less material than the ordinary type of ilat wire spring which is formed of a series of alternately the like, a flller or padding I1, and a fabric cover I8. In securing the upholstery material adjacent the spring, the material is pulled taut over the spring and secured in place. When pulled taut the bottom piece I6 only engages the curved pinch the upholstery than the ordinary `ilat oppositel'y'facing U-shaped undulations and that,

therefore, the spring may be constructed more i cheaply than the ordinary type of spring.

While the spring has been particularly shown and described it is within the scope of this inwire having lateral undulations-forming alter-k ing a longitudinal curvature, said U-shaped por'- tions being flat.

SAMUEL S. BERNSTEIN. 

